Drug Interactions between fedratinib and propafenone

Consumption of grapefruit, grapefruit juice, and supplements that contain grapefruit should be avoided during treatment with propafenone as they may increase the blood levels of propafenone in some patients. This can cause serious side effects such as new or worsening irregular heart rhythm or heart failure; chest pain; difficulty breathing; fluid retention and swelling; and slow heart rate and pulse. Talk to your doctor if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Grapefruit juice can increase the blood levels of fedratinib. This may increase the risk of serious side effects such as Wernicke's encephalopathy, a potentially fatal condition of the brain associated with thiamine (vitamin B1) deficiency; low blood cell counts, which can lead to anemia, bleeding, and infections; severe diarrhea, nausea, and vomiting; problems in the liver or pancreas; and development of other cancers. You should avoid the consumption of grapefruit and grapefruit juice during treatment with fedratinib. You may take the medication with or without food, but taking it with a high-fat meal may help reduce nausea and vomiting. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.